Relay counting circuit



April 22, 1952 E. R. LIBERG RELAY COUNTING CIRCUIT Filed sept. 15, 1949[lll mung. .as

Patented Apr. 22, 1952 2,593,578 RELAY ooUNTrNG CIRCUIT Edwin R. Liberg,Brooklyn, N. Y., assigner to Radio Corporation of America, a corporationof Delaware Application September 15, 1949, Serial No. 115,865

4 Claims.

The present invention relates to electrically operated calculatingequipment, and more specifically to improved apparatus for convertingnumbers expressed in a nrst radix to numbers expressed in asecond radix.

The primary object of my present invention is to provide improvedapparatus to receive information in the decimal system, or radix ten,and translate this information into the binary system, or radix two.

Another object of my present invention is to provide an improvedcounting system which may be easily expanded or continued in any desirednumber of digits in the manner shown and described herein.

These and other objects are achieved in accordance with my presentinvention by using a plurality of relays connected in tandem to a sourceof sequential pulses. The relays are of the type that have two opposingwindings and are operated by a first pulse and remain operated until asecond pulse is applied, when the relay is released. The relays areinterconnected so that each relay receives pulses from the sourcethrough preceding ones in said series when the preceding ones are alloperated. By using the combinations provided by the coinciding closureof contacts associated with each of the relays, a pulse input equal innumber to a desired decimal number will operate the relays to providethe proper radix two equivalent number. The radix two number isindicated by an indicator, such as one utilizing lights.

The novel features of the invention, as well as the invention itself,both as toits organization and method of operation, will best beunderstood from the following description when read in connection withthe accompanying drawings in which:

Figure 1 is a schematic circuit diagram of an embodiment of myinvention, and

Figure 2 is av chart showing the operating sequence of the relays usedin the embodiment of my invention shown in Figure l.

The radix of any numbering system is a number which is ythe base of thatsystem. Thus, ten is the radix of the decimal system and two is theradix of the binary system. To convert a number from radix l to radix 2,the radix number is expressed as multiples of two and l then a ten issubstituted for eachtwo that appears in theradix ten number expressed inmultiples of two. For example, 16'is expressed as 24..; andin thefbina'ry system, its equivalent is 1045::10000. v'As' another example,19 is ex- 'contacts I 8, `24 of relay BB1.

pressed as 24 plus 21 plus 20, which corresponds to 104 plus 101 plus100:10011. More complete discussion of the binary and similar systems ofcomputation may be found in Elementary Number Theory by Uspenski andHeaslett, Mathamatical Excursions by H. A. Merrill and A MathamaticianExplains by M. I. Logston.

Referring, now, to Figure l, a source of an arithmetical train ofelectrical pulses III is connected to a timing relay I2 which is soarranged as to permit only a portion of an applied pulse to enter theline to a plurality of counting relays AAi, BB1 NN1 through its contactsI4, I6 when it operates to break the circuit to the line. The purpose ofthe timing relay I2 is to assure that only uniform pulses are applied tothe counting relays. However, if the input pulses all have a"similartimed duration, the timing relay I2 may be omitted and the input pulsesmay be applied directly to the line to the counting relays and they willoperate properly.

The counting relays AAi, BB1 NN1 are of the double coil, neutral relaytype. Each relay has a pair of normally closed contacts I8, 20 which areconnected between the pulse input to the relay and one of two coilwindings 22, and apair of normally open contacts 24, 26 which areconnected between the pulse input to the relay and to the other coilwinding 28. The latter coil winding 28 is connected to oppose the formercoil winding 22. Each coil winding has a current limiting resistor 29 inseries with it. A first pulse applied to any one of the counting relaysis applied to the coil winding 22 through normally closed contacts I8,20, thereby operating the relay and opening the normally closed contactsI8, 20. A hold in contact 30 which is connected to an operating biassource 32 through a current limiting resistor 34 engages the contact 2Uthus connecting the bias source to the coil winding 22 and holding therelay operated. The normally open contacts 24, 26 are also closed byoperation of the relay. A second pulse supplied to any one of thecounting relays which is operated is applied through the now closed, butnormally open, contacts 24, 26 to the opposing coil winding 28. Thisreleases the relay and restores the former conditions.

Counting relay AA1 has its contacts I8 and 24, the respective ones ofthe normally closed and normally open contacts not connected to the coilwindings 22, 28, connected to the pulse source l0 through the timingrelay contacts I4,

le; l Contact 2 6 of relay AA1 is connected-to Contact 25 vof 'ral layBB1 is connected to contacts l, 24 of relay- NN1. It may therefore beseen that the counting relays of the counting chain are allinterconnected in tandem in such fashion that they are all connected tothe pulse source IB through preceding relays in the seriesinterconnection only when all preceding relays are operated.

A rst'pulse applied to the rst relay AA1 in the series from the timingrelay i2 operates the first relay AA1. A set of auxiliary contacts 3Gassociated with relay AA1 and connected to a functional power supply 38is also operated, causing an or standby light of an indicator 60 to beextinguished and a l light to be operated. The circuit to the l lightmay be traced from the functional input power supply 38 through theauxiliary contacts 36 associated with the rst counting relay AA1, theauxiliary contacts l0 associated with the second counting relay BB1, andthe auxiliary contacts 46 associated with the third counting relay NN1through the 1 light to ground.

A second pulse from the timing relay i2 is applied, simultaneouslythrough the AA1 now closed but normally open contacts 2li, 26 to theopposing winding 28 of the first relay AA1 thusreleasing the relay AA1and through the BB1 normally closed contacts i8, 20 to the winding 22 ofrelay BB1, thus operating the second counting relay BB1. auxiliarycontacts 36, 42, 48 as a result of only the second relay BB1 beingoperated, the 10 light is lit and the l light is extinguished.

A third pulse applied from the timing relay l2 now causes only the firstcounting relay AA1 to be operated. Relay BB1 remains operated. Theauxiliary contacts 36, i, 4, as a result of, the first and secondcounting relays AA1, BB1 now being operated, illuminate the 11 light andextinguish the 10 light.

A fourth pulse applied from the timing relay l2 is simultaneouslyapplied through their now closed but normally open contacts 24, 2t tothe opposing coils 23 of the first and second counting relays AA1, BB1,thus causing them to be released, and through. the NN1 normally closedcontacts I8, 29 to the coil 22 of the third counting relay NN 1, causingthe latter relay to be operated. The auxiliary contacts 35, 42, 5B as aresult oi only the third counting relay NN1 being operated illuminatethe 100 light and the 1l light is extinguished.

A fifth pulse applied by the timing relay l2 operates the first countingrelay AA1 again. Counting relay NN1 remains operated. The auxiliarycontacts 36, L10, 36 cause the 181 light tovbe illuminated as a resultof the rst and third counting relays being operated and the 100 light isextinguished.

A sixth pulse applied by the timing relay l2 operates the secondcounting relay BB1 and releases the rst counting relay AA1. Countingrelay NN1 remains operated. The auxiliary contacts 36, 42, d8 cause the110 light to illuminate, in view of the second and third relays BB1, NN1being operated and the 101 light is extinguished.

A seventh pulse applied by the timing relay l2 operates the iirstcounting relay AA1. Counting relays BB1 and NN1 remain operated. Theauxiliary contacts illuminate the 111 light as a result of all thecounting relays being operated and the 1.10 light is extinguished.

An eighth pulse from the timing relay releases all the relays, the.clight is illuminated again In view of the circuit now made by the 9indicating that the system is reset for a new counting cycle.

Figure 2 shows the operating sequence of the counting relays. That therelays operate in binary fashion in response to the decimal Sequence ofinput pulses may be readily seen from this chart.

Although only three relays are used in the embodiment of my inventionfor a total decimal count of seven this should not be taken as alimitation of my invention. As high a count as is desired may beobtained merely by connecting the required number of relays in tandem inthe manner shown in Figure 1. The number of relays required in acounting! chain for a desired count may be obtained from the followingformula:

where C is the desired count, and n is the number of relays required inthe counting chain.

In place of the lights to indicate the binary number equivalent of thenumber of input pulses, relays or any other mechanism may be inserted tobe operative in response to a desired binary count.

From the foregoing description, it will be readily apparent that I haveprovided a system for converting any decimal number of pulses which aresupplied in sequence into its corresponding binary number with provisionfor operating other mechanisms accordingly. Although I have shown anddescribed but a single embodiment of my present invention, it should beapparent that many changes may be made in the particular embodimentherein disclosed, and that many other embodiments are possible allwithin the spirit and scope of my invention. Therefore, I desire thatthe foregoing description shall be taken as illustrative and not aslimiting.

I claim as my invention:

1. A relay counter comprising a plurality of relays, each of said relayshaving a pair of opposing coil windings, iirstand second normally closedcontacts, said rst contact being connected in series with one of saidpair of opposing windings, a third Contact positioned to engage saidfirst contact when said relay is operated, means to apply a bias to saidthird contact to maintain said relay operated when said rst and andthird contacts are closed and the other of said pair of opposed windingsis not energized, and iirst and second normally open contacts, saidiirst normally open contact being connected to the other of said pair ofopposing coil windings, means to impress pulses simultaneously upon saidsecond normally closed contact and said second normally open contact ofa rst one of said plurality of relays, each one of the remainder of saidplurality of relays having its second normally closed contact and itssecond normally open contact connected to the first normally opencontact of the preceding one of said plurality of relays.

2..A relay binary counter comprising a plurality of tandem connectedrelays, and means to apply pulses to be .counted to a Viirst" one ofsaid relays; each of saidvrelays having a pair of opposing windingswhereby application of a pulse to one of said pair of opposingA windingsoperates said relay and application of a pulse to the other of said pairof windings releases said relay each of said relays also having rstcontact means to apply: a first pulse applied to said.

relay to said oneof said windings to operate said relay, meanstomaintain said relay operated when operated, and second contact meansresponsive to said relay being operated to apply a second pulseappliedto said relay to a succeeding one of said'ta'ndem connected relays andto said other of said pair of windings to release said relay.

3. A relay-counter comprising a plurality of relays connected in tandem;each of said relays having a pair of opposing windings, means to operatesaid relay including a pair of normally closed contacts in circuit withone of said opposing windings,means for holding said relay operatedthrough said opposing winding responsive to the operation of said relay,means to release said relay including a pair of normally open contactsin circuit with the other of said opposing windings; means to applypulses to be counted sequentially to the means to operate and means torelease of a rst one of said tandem connected relays; and means couplingthe means to operate of each of the remaining relays to the normallyopen contacts of the means to release of a preceding relayv whereby saidrelays operate in binary fashion responsive to a succession of pulsesapplied to said iirst one of said tandem connected relays.

4. A relay counter comprising a plurality of relays connected in tandem,each of said relays having a pair of opposing windings, a pair of 'saidopposing windings through the normally open contacts when closed Vtorelease said relay, and means coupling said means to apply a first,pulse and a second pulse of each relay to the normally open contacts ofa preceding relay.

EDWIN R. LIBERG.

REFERENCE-S CITED The following references v-are of record in the illeof this patent:

UNITED STATESf PATENTS j Number Name Date 1,563,738 From Dec. 1, 19251,813,969 Smith July 14, 1931 1,904,929 Richardson Apr. 18, 19332,205,555 Cooper June 25, 1940 2,318,591 Cougnal May 11, 1943 2,364,540Luhn Dec. 5, 1944 2,375,413 Guenther May 8, 1945 2,389,275 Rayner Nov.20, 1945 2,451,489 Joel Oct. 19, 1948 2,452,051 Hersey Oct. 26, 1948

